The correct answer is A. On Kingship.
Explanation
Saint Thomas Aquinas (1224 - 1274) was an Italian Catholic philosopher and theologian, one of his most important works was the interpretation of the work of Aristotle, also he was known for his book "On Kingship", which covers issues such as political power, laws, justice and more importantly the government role and nature. This book caused a stir during Aquinas' time because it was a precedent of political philosophy that raised questions about nature, religion, and government in the monarchy. So, the correct answer is A. On Kingship.
